Aaron Williamson, a former US marine and bodybuilder, has posted a series of images of Simmons in the gym over the last few weeks, as the Whiplash star prepares for the role of Commissioner Gordon in DC Comics’ Justice League film, out next year.

“When you look at him in the gym people are literally doing double-takes,” Williamson told The Hollywood Reporter.

“They can’t believe that’s him. He’s doing such a good job of being disciplined and staying dedicated to doing something he hasn’t done before with his physique. He’s ripped. He’s more shredded than I am.”

Commenting on whether the training was for Simmons’ upcoming film role, Williamson said: “As far as the whole Justice League stuff goes, if he is trying to get ready for something in that arena, I’m not aware of it and he never shared it with me. I’m only training with him as a friend and client and helping him achieve what he’s trying to achieve with his new physique.”

Justice League Part One will be directed by Zack Snyder. It will feature heroes Batman (Ben Affleck), Superman (Henry Cavill), Wonder Woman (Gal Gadot), Aquaman (Jason Momoa), the Flash (Ezra Miller) and Cyborg (Ray Fisher) teaming up together. It’s due for release in November 2017, and will be followed up with a sequel in 2019.